Casper Cool Supima Sheet Set Review

We purchased a set of Casper's Cool Supima Sheets so our writer could put it to the test. Keep reading for our full product review.

The Casper company, originally known for its mattresses, expanded its line to include sheets, pillows, and other bedding items. Their goal is to “re-imagine sleep from the ground up.” We tried the Casper Cool Supima Sheet Set to test for comfort, breathability, and dependability. Do these sheets live up to their promise to become softer and more luxurious over time? 

Material: Superior Supima

These sheets are made from Supima-branded cotton, durable, extra-long-staple cotton that’s similar to Egyptian cotton. To be called Supima, it must be grown in the U.S. Supima cotton makes up only 1 percent of the cotton in the world. It is grown in only four states in the US: California, Arizona, Texas, and New Mexico. 

The Supima cotton in these sheets, which Casper claims is 45 percent stronger and 35 percent longer than regular cotton, is grown on a farm in California’s central valley. However, the sheets are spun, woven, and sewn in India. The material used is OEKO-TEX 100-certified, which means it's been heavily tested for and found free of a long list of potentially harmful chemicals.

Thread Count and Weave: Breathable percale

Think about more than thread count when looking for the perfect sheet. Weave is equally important. These sheets are percale, which means it is made with a traditional weave that involves plying one thread vertically and one thread horizontally. The weave gives the sheets a classic smooth, tight pattern with a matte finish. Known for its breathability, percale can be used in all seasons and is ideal for people who are “hot sleepers.” To be considered percale in the United States, the fabric must have a thread count of at least 180. The optimal range for quality will vary between 250 and 500. These sheets have a thread count of 400 and fall in the right range to be supremely soft, yet cool to the touch. Snuggling into these sheets each night felt like we were slipping into bed at a luxury hotel. 

Texture: Thick and crisp 

Percale sheets have a crisp texture that resists pilling, which are the small fiber balls that pop up on the surfaces of sheets. These sheets become softer with each wash. The Casper sheets felt crisp straight from the package and kept their crispness after several washes. Although the material felt thicker than other sheets we’ve tried, we didn’t become too warm during the night. 

Washing: Air dry to prevent wrinkles

To prevent shrinkage and destroying cotton fibers, wash the sheets in cold water on a gentle cycle. The manufacturer recommends drying on a low setting and removing from the dryer as soon as possible to prevent wrinkling. We found, after closely following these instructions, the sheets still wrinkled. One solution is to air dry the sheets and smooth out the wrinkles by hand. This helped, but to get a cool, crisp finish the sheets need to be ironed. 

Color: A few color contrasts 

Casper Cool Sheet Sets come in two solid colors: white and cream. There are also three sets with a contrasting hem available: navy and azure, white and gray, and sky and azure. We chose white, and it has kept its bright appearance after repeated washings.

Key Features: Making the bed has never been so easy

Fitted sheets with elastic around all sides are a sign of quality. The Casper fitted sheet has a thick band of elastic that holds the sheet firmly in place. I had trouble with one corner popping off before I finished making the bed, but I believe this was caused by the depth of my mattress.  

Small tags on two sides give visual clues as to where to place the shorter ends of the sheet. Pillowcases stay securely in position with pillow flaps located inside the cases.

Price: Worth the splurge

Any product bearing the Supima trademark is strictly regulated by the Supima Association for quality and authenticity. In fact, they can guarantee whether it’s a real or fake product by using DNA coding. This also means Supima products will have a higher price tag. While the price ranges from around $90 for twin-size to $140 for California King, Supima-branded cotton is a luxury item that will last for years with proper care. 

If you feel the sheets do not match the description, Casper offers a 100-night trial, allowing you to test the product in your home. If you are not satisfied, Casper will give you a full refund with free return shipping. There’s also a 1-year limited warranty on materials and defects caused by normal use.

Competition: Supima, Egyptian, and regular cotton variations

Mellanni 100% Cotton Sheet Set: These 300-thread-count regular cotton sheets (view on Amazon) were the least expensive of the sheet sets we tested and also the thinnest. Available in five neutral colors, these sheets have a glossy sateen finish. Pleasantly soft and easily wrinkled, they’re a good budget-friendly option that works great in a guest or kid’s room. They also have a lifetime 100 percent satisfaction money-back guarantee if you are dissatisfied for any reason.

Pinzon 400-Thread Count Egyptian Cotton Sateen Hotel Stitch Sheet Set: Amazon sells this sheet set as its luxury bath and bedding brand. A mid-priced brand, their fitted sheets (view on Amazon) have quality features like a full-length elastic band and deep pockets for a snug fit. While they have a tendency to wrinkle, the soft sateen finish and the color bands give these sheets an upscale feel. 

Two of the key differences between all three of these companies were pocket depth and softness. Pinzon fitted sheets are designed to fit a 15-inch mattress, while Mellanni can fit a 16-inch mattress. Casper fitted sheets are the least deep, fitting a 14-inch mattress. Anyone who uses a memory foam or pillow top mattress might want to measure the mattress to make sure the sheets will fit properly. Another difference is the degree of softness. Casper sheets were the most comfortable, becoming softer after each wash while still retaining their crisp feel.